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Biomedical subjects

M L Colombo

Publications and source records attributed to M L Colombo.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Cytotoxicity evaluation of natural coptisine and synthesis of coptisine from berberine.

The crude extract (80% MeOH in water) of Chelidonii herba exhibited very interesting cytotoxicity against brine shrimp (Artemia salina Leach) nauplii and cultured human tumour cell in vitro, the colon carcinoma HT 29 (144 h treatment). Fractionation of the crude extract and bioassay-guided procedures showed that the cytotoxic and the antitumour activities were concentrated in the basic extract. On the basis of IR, MS and 1H NMR the compound responsible of the cytotoxic activity was determined to be coptisine. Cytotoxicity evaluation of coptisine was next extended to a panel of human and murine cell lines in comparison with the established antitumour drugs mitoxantrone, doxorubicin (Dx) and cisplatin (CDDP). Coptisine was cytotoxic on LoVo and HT 29 and less potent on L-1210, and it was partially crossresistant on the human tumour colon cell line resistant to Dx, LoVo/Dx, whereas it was not significantly crossresistant on the murine leukaemia cell line resistant to CDDP, L-1210/CDDP. Coptisine alkaloid was then synthesised in gram amount from commercial berberine. A four-step synthetic route was elaborated. The overall yield was about 8-10%. The structural identity of synthetic coptisine was verified by IR and NMR methods. A comparison of the cytotoxic effects on the human tumour colon cell line LoVo and on the murine leukaemia L1210 showed, for both natural and synthetic coptisines, a comparable cytotoxic activity more evident against HT 29 cell line and LoVo cell line, while the activity was lower against the L1210 cell line.

Animals↗
PubMedDate not supplied

Flavonol glycosides from Dryas octopetala.

Six flavonol glycosides and ent-epicatechin were isolated from Dryas octopetala and their structures elucidated by chemical and spectroscopic methods. Two new flavonoids, 3-O-alpha-L-arabinofuranosyl-8-methoxyquercetin (2) and 3-O-beta-galactopyranosyl-8-methoxykaempferol (6), were identified along with 3-O-beta-D-galactopyranosylquercetin (hyperin) (3), 3-O-alpha-L-arabinofuranosylquercetin (avicularin) (5), 3-O-beta-L-arabinopyranosylquercetin (4), and 3-O-beta-D-galactopyranosyl-8-methoxyquercetin (1).

Chemical Phenomena↗
PubMedDate not supplied

[Thyroid function in children with Down's syndrome].

The aim of the present study was to evaluate thyroid function in 45 Down's syndrome patients in order to verify the hypothesis of an increased risk of thyroid disorders associated with trisomy 21. A patient with subclinical hypothyroidism (TSH 16.6 microU/ml; T4 6.4 micrograms/dl) was diagnosed in a group of 28 subjects with Down's syndrome studied at a mean age of 6 years and 5 months using T3, T4, FT3, FT4, TSH assays and clinical examination. T4 and TSH values were also measured in 10 of these children at the neonatal screening. One infant presented transient neonatal hyperthyrotropinemia but later became euthyroid. The analysis of thyroid hormone values at the neonatal screening of other 17 subjects with Down's syndrome did not reveal other cases with thyroid function disorders. The results of this study highlight that altered thyroid functions are evident in children with trisomy 21 associated with heart anomalies. A careful clinico-endocrinological follow-up of patients with Down's syndrome is recommended in order to ensure an early diagnosis of thyroid function disorders and/or autoimmune diseases which might complicate the evolution of trisomy and negatively affect outcome.

Adolescent↗
PubMedDate not supplied

[Cholesterol screening in a pediatric population at atherosclerotic risk].

We studied 344 children (174 girls and 170 boys) between the ages of 6 and 15 years (average age 11 years 9 months) chosen on the basis of a positive family anamnesis for dismetabolic and/or precocious cardiovascular pathologies, and also on the basis of objective data obtained at medical examinations, such as obesity and hypertension. These subjects underwent blood tests for glycaemia, total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. Children with total cholesterol levels above 170 mg/dl were considered to be hypercholesterolemic. 127 young people (65 girls and 62 boys) turned out to have excessively high cholesterol levels with an average level of 195.71 +/- 23.11 mg/dl and average LDL level of 127.05 +/- 25.08 mg/dl. 217 subjects (109 girls and 108 boys) turned out to be within the norm with total cholesterol level of 137.76 +/- 23.04 mg/dl and LDL cholesterol 75.59 +/- 22.89 mg/dl. We found a greater difference between the average values of LDL cholesterol and those of total cholesterol (40.5% compared to 29.61%), which shows that even at pediatric ages the LDL cholesterol concentration is the factor which best indicates the risk level for atherosclerotic development.

Adolescent↗
PubMedDate not supplied

[Selenium in the full-term and premature newborn infant].

The following observations can be made on the basis of findings relating to selenium in serum samples taken from 55 neonates (35 born at term and 20 born pre-term): 1) the blood concentration of selenium in neonates born at term showed no substantial difference to that reported by other authors; moreover, there were no sex or birthweight-dependent variations, and no correlations were found with either the mother's age or the mode of engendering procreation; 2) the blood concentration of selenium in neonates born pre-term was 30% lower than that found in neonates born at term; it was correlated with gestational age and birthweight, but not with sex, mother's age or the mode of engendering procreation. It will be worthwhile continuing these tests in order to identify possible therapeutic uses of selenium in cases of deficiency.

Birth Weight↗
PubMedDate not supplied

[In vitro antibacterial activity of neomycin, bacitracin and a combination of both].

Bacitracin and neomycin have been used for a long time for local intestinal antisepsis or decontamination, due to their scarce or nonexistent intestinal absorption. The aim of the present study was to determine the activity of bacitracin and neomycin against recent clinical isolates of aerobic and anaerobic microorganisms and to verify their capacity to have a synergistic effect and to prevent the emergence of bacterial resistance when in combination. The results showed that the activity of either antibiotic against recent clinical isolates (even if resistant to cephalosporins and aminoglycosides) is similar to that originally displayed at the time introduction in therapy. Generally the combination of the two antibiotics showed a synergistic or additive effect and prevented the selection of resistant strains.

Bacitracin↗
PubMedDate not supplied

[The safe transportation of children in automobiles].

The Author emphasizes the significant number of children who sustain fatal accidents during their transport on motor vehicles and relates the Act recently promulgated by the Italian Parliament on the mandatory use of particular restraining devices as well as safety harness for children.

Accidents, Traffic↗